Introduction

My early compositions, towards the end of 1970s, were written in a style deriving from impressionism. My interests were particularly concentrating upon the harmonic, vertical aspect of musical composition: in this I had been influenced by my first teacher of Composition, Bianca Maria Furgeri.
Aleksandr Skrjabin’s works, often constructed upon a unique chord which incessantly undergoes continuous transformations, have been an important reference point. In Skrjabin’s “Prometheus”, for example, the basic chord, as a matter of fact named “Prometheus chord”, preferably connects with its transpositions at ascending and descending minor thirds and tritone intervals. Practically, all chords placed along the axis of a diminuted seventh are considered as belonging to a unique family, as they connect more frequently among them than with others.
In studying the various possibilities of connecting any chord with the transpositions of itself, I came to the point  of identifying  real modal families which are proper to every chord, given by the larger or smaller amount of notes in common in its transpositions.
This research had some contact points with the set-theory. In particular, the “interval vector”, formerly theorized in the 1950s by Hanson in his classic “Harmonic Material of the Modern Music” and then developed further by Forte, is nothing but a numerical succession expressing the notes in common between a given set (chord) and its proper transpositions: on the basis of the set taken into consideration, the possibilities may remarkably vary.
Thus, I started to compose several pieces based on a unique chord, which used to connect with itself according to planned transposition levels. After indentifying  one reference (fundamental) note of the chord, a series of more or less complex numbers indicated the succession of the transposition levels: if the series repeated itself cyclically, longer or shorter canons would derive. In transcribing the numerical series upon a geometrical figure corresponding to the dodecaphonic whole (a dodecagon), there would derive more or less complex geometrical figures, which I have named musical kaleidocycles, in  a sort of regular division of the sound space; I have also worked out colour graphical transpositions of some successions, assigning one colour to every pitch, so as to compose lively multicolour panels, with various pictorial and decorative techniques.
The first piece composed after this technique was “Fughetta su un solo accordo” (1986); in deepening the potentialities of this composing approach, I continued my research with several compositions as “Rodion” and “Organum” (1991) and with “Tre Caleidocicli” and "I Nuovi caleidocicli” (1991), all of which were created upon the transpositions of a unique chord, often accompanied by its opposite or by complementary one. In “Moto perpetuum” (1991) the chords used were two, precisely the major and the minor  triads; in “Notturno”, on the contrary, the material used was exclusively based upon three four-note chords, which altogether completed the dodecaphonic whole. “Riflessi lunari” (1990) and “Landscape" (1992),
for two opposite instrumental groups, were created upon a unique chord and their opposite. The latest compositions written according to this system date back to 1995. More recently I have written pieces using a more varied harmonic material, in particular “Acquerelli abruzzesi” and “Sei liriche su testi di Agnese Metta” for soprano and piano, where it is possible to perceive Mediterranean echoes and  frequent  reference to the Italian melodrama tradition. Besides, it is worth while mentioning a few series of piano pieces which develop freely the theory of transpositions of a unique chord: “Tre Studi” (1994), “Due Danze” (1996), “Opposite-Scherzo” (1997), “Cinque Preludi in forma di variazioni” (1998), “Toccata e Ciaccona” (1998), “Variazioni” (2000).
I have always paid particular attention to the so called “light” repertoire and to “common” music, composing pieces for CD ROM, publicity intermezzi, music for documentary films, music for films and arrangements.
My theoretical research is particularly condensed in my treatise “Organizzazione delle altezze nello spazio temperato”.

Bibliographical references

Renzo Cresti, Luigi Verdi, Caleidocicli e canoni, in “Musica presente. Tendenze e compositori di oggi”, Lucca, LIM, 2019, pp. 339-343.

Alberto Colla, I caleidocicli musicali (1990) di Verdi, in “Trattato di armonia moderna e contemporanea”, vol. I, Le simmetriche terre promesse, Milano, Carisch, 2016,  pp. 263-279.

Piero Mioli, Dizionario di musica classica. Dalle origini a oggi. Gli autori, le scuole, gli esecutori, le musiche, Milano, Rizzoli, 2006, pp. 1952-953.

Luigi Verdi, Quaderni di Octandre, 13, Agenda Edizioni musicali, Bologna 1999.

“Enciclopedia italiana dei compositori contemporanei”, a cura di Renzo Cresti, Pagano Editore, Napoli 1999.

“Musicisti contemporanei. Compositori e musicologi, panorama biografico” a cura di Otello Calbi, Edizioni Cembalo, Napoli 1994.